package com.fzy.common.threadpool;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;

public class CustomThreadPool {

    private static Logger logger = LoggerFactory.getLogger(CustomThreadPool.class);

    private ThreadPoolExecutor pool = null;


    /**
     * 线程池初始化方法
     * <p>
     * corePoolSize 核心线程池大小----1
     * maximumPoolSize 最大线程池大小----3
     * keepAliveTime 线程池中超过corePoolSize数目的空闲线程最大存活时间----30+单位TimeUnit
     * TimeUnit keepAliveTime时间单位----TimeUnit.MINUTES
     * workQueue 阻塞队列----new ArrayBlockingQueue<Runnable>(5)====5容量的阻塞队列
     * threadFactory 新建线程工厂----new CustomThreadFactory()====定制的线程工厂
     * rejectedExecutionHandler 当提交任务数超过maxmumPoolSize+workQueue之和时,
     * 即当提交第41个任务时(前面线程都没有执行完,此测试方法中用sleep(100)),
     * 任务会交给RejectedExecutionHandler来处理
     */
    public void init() {
        pool = new ThreadPoolExecutor(
                1,
                3,
                30,
                TimeUnit.MINUTES,
                new ArrayBlockingQueue<>(5),
                new CustomThreadFactory(),
                new CustomRejectedExecutionHandler());
    }

    public CustomThreadPool() {

    }

    public void init(int corePoolSize, int maxinumPoolSize, long keepAliveTime, int capacity) {
        pool = new ThreadPoolExecutor(
                corePoolSize,
                maxinumPoolSize,
                keepAliveTime,
                TimeUnit.MINUTES,
                new ArrayBlockingQueue<>(capacity),
                new CustomThreadFactory(),
                new CustomRejectedExecutionHandler());
    }

    public void destory() {
        if (pool != null) {
            pool.shutdownNow();
        }
    }


    public ExecutorService getCustomThreadPoolExecutor() {
        return this.pool;
    }

    private class CustomThreadFactory implements ThreadFactory {

        private AtomicInteger count = new AtomicInteger(0);

        @Override
        public Thread newThread(Runnable r) {
            Thread t = new Thread(r);
            String threadName = CustomThreadPool.class.getSimpleName() + count.addAndGet(1);

            logger.info("threadName={}", threadName);

            t.setName(threadName);
            return t;
        }
    }


    private class CustomRejectedExecutionHandler implements RejectedExecutionHandler {

        @Override
        public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
            try {
                // 核心改造点，由blockingqueue的offer改成put阻塞方法
                executor.getQueue().put(r);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }


}
